{"id":29811,"date":"2022-02-28T13:58:24","date_gmt":"2022-02-28T13:58:24","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=105181"},"modified":"2022-02-28T14:06:13","modified_gmt":"2022-02-28T14:06:13","slug":"when-can-we-expect-james-webb-space-telescopes-first-images","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/when-can-we-expect-james-webb-space-telescopes-first-images\/","title":{"rendered":"When can we expect James Webb Space Telescope\u2019s first images?"},"content":{"rendered":"

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By Govert Schilling\n \t\t<\/p>

Published: Monday, 28 February 2022 at 12:00 am<\/p>

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A<\/span>fter 25 years and over 10 billion US dollars, on Christmas Day 2021, the James Webb Space Telescope (JWST) was finally launched into space by a European Ariane 5 rocket.<\/p>\n

With its 6.5-metre primary mirror and its tennis-court-sized sunshield, Webb had to be folded up to fit in the rocket\u2019s fairing, only to be deployed step by step in the first two <\/span>weeks of its mission.<\/p>\n

Now, we\u2019re all eagerly awaiting the first proper images of space captured by the James Webb Space Telescope<\/a>, which should be captured around June or early July 2022.<\/p>\n

Find out how James Webb Space Telescope will study galaxies<\/a>, and how James Webb Space Telescope will study exoplanets<\/a>.<\/strong><\/em><\/p>\n

\""The\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
The launch of the James Webb Space Telescope aboard Arianespace\u2019s Ariane 5 rocket from French Guiana on 25 December 2021. Credit: Jody Amiet\/AFP via Getty Images<\/span><\/figcaption><\/div>\n

Currently, the James Webb Space Telescope is aligning its primary mirror using its Near Infrared Camera (NIRCam) instrument, which has resulted in the image below: a mosaic of the same star captured 18 times.<\/p>\n

This seemingly chaotic capture is a result of JWST\u2019s unaligned mirror segments reflecting light back into the telescope\u2019s instruments, and is a vital part of preparing Webb for producing beautiful images of the Universe.<\/p>\n

\""A\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
A mosaic of the same star captured 18 times captured by James Webb Space Telescope. This image was used by NASA scientists to align JWST\u2019s primary mirror. Credit: NASA<\/span><\/figcaption><\/div>\n

A total of three mid-course correction manoeuvres successfully placed the huge space telescope in a slow looping orbit around the second Lagrange point (L2), a stable gravitational point some 1.5 million kilometres behind Earth as seen from the Sun.<\/p>\n

\u201cBut a lot more needs to be done before we can start science operations,\u201d says Mark McCaughrean, the Senior Advisor for Science and Exploration at ESA (the European Space Agency), NASA\u2019s main partner in the programme.<\/p>\n

For one, the telescope and its sensitive instruments, which left the French Guiana launch platform at tropical temperatures, have to cool down to 230\u02daC below zero.<\/span><\/p>\n

\""In\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
In this image captured by cameras on the upper stage of its Ariane 5 rocket, JWST sets off on its 1.5 million km voyage to L2 after separating on 25 December 2021. Credit: Arianespace\/ESA\/NASA\/CSA\/CNES<\/span><\/figcaption><\/div>\n

Thanks to its giant multi-layer sunshield, JWST had already reached \u2013200 \u00b0C by early January 2022, but the passive cooling slows down over time.<\/span><\/p>\n

It\u2019s a delicate process, says McCaughrean. The optics can never be the coldest parts of the telescope, lest molecules released as gases from the graphite-composite support structure freeze down on the mirrors, degrading its performance.<\/span><\/p>\n

When the NIRCam instrument (Near Infrared Camera) got cold enough for its sensitive mercury-cadmium-telluride detectors to pick up infrared light, the process of aligning the telescope\u2019s 18 mirror segments could finally commence.<\/p>\n

Each hexagonal segment is fitted with seven actuators and can be slightly tilted, shifted, rotated and deformed to ensure that they operate together as one perfect parabolic surface.<\/p>\n

And since the alignment procedure is done with starlight, the image above marks JWST\u2019s \u2018first light\u2019.<\/p>\n

But it will take months of incremental precision adjustments before the 18 individual stellar images from each mirror are all brought together into one single focus.<\/p>\n

\""Webb\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Webb will orbit the L2 point, keeping the Sun, Earth and Moon behind it for a clear view of deep space.<\/span><\/figcaption><\/div>\n

Testing JWST\u2019s instruments<\/strong><\/h2>\n

Around late April 2022, engineers will also start commissioning JWST\u2019s four large science instruments:<\/p>\n